A west-facing terrace roof with a chimney in the way, turned into a 12-panel array with a battery under the stairs.
The brief
Hannah and Dayo wanted to stop paying peak rates after 5pm. The roof faces west and loses an hour of light to the neighbour’s chimney stack.
What we fitted
Twelve 400 W all-black panels on two strings with optimisers on the shaded row, a 5 kW hybrid inverter and a 5.2 kWh battery tucked under the stairs.
Twelve months on
The array produced 4,410 kWh in its first year, 2% ahead of our estimate. Evening grid import has dropped by 68%.
Field plate · STC
Pmax · rated output
4.8
kWp
Panels
12 × 400 W
Battery
5.2 kWh
Yield / yr
4,320 kWh
Payback
8.1 yrs
CO₂ saved
1.4 t/yr
Roof
Pitched
Switched on
Jun 12, 2025
Want a plate like this for your roof?
17:05
On the roof
18:30
In their words
They mapped every shadow on our roof before quoting. A year in, we buy 68% less from the grid after five o’clock.
Hannah Okafor
Douglas, Cork